The subject matter of the present invention includes a composition for decolorizing fibers and a process for decolorizing fibers using that composition as well as a multi-part kit for dyeing and subsequently decolorizing of fibers, especially human hair, which contains both a composition for dyeing the fibers and also the composition according to the invention for decolorizing the fibers.
Oxidative dye compositions are outstandingly suited for covering a large portion of gray. The oxidative dye compositions used to dye hair which is up to about 50% gray are called tinting compositions, while the oxidative dye compositions usually used to dye hair that is up to 100% grey color or for brightly coloring hair are called oxidative hair dyes.
Direct-dyeing dye compounds, especially nitro dye compounds, are widely used in non-oxidative dye compositions. Because of their small size they are able to penetrate in the hair and to directly dye at least the outer portions of the hair. This sort of dyeing is very safe and usually stands up to several hair washings.
Direct-dyeing dye compounds, especially nitro dye compounds, are frequently used in oxidative dye compositions to produce certain nuances or for intensifying the dyeing. Generally colored polymers produced oxidatively in the hair have a high resistance to external influences, such as water, shampoo or light. According to the dyeing arts they are firmly anchored so that generally they remain in the hair until the next hair cut. If removal of the dyed color is desired, a comparatively reactive chemical, such as formaldehyde-sulfoxylate, hydrogen peroxide or hydrogen peroxide addition products may be used. An extensive decolorizing or bleaching is also possible, however this type of treatment can damage the hair or have a deleterious effect on the health of the individual treated.
A partial decolorizing of non-oxidatively tinted hair is usually possible by multiple hair washings, but a complete removal of the color of the dyed hair is not possible in this way.
If a special hair color is desired, but for only a short time, the hair must first be dyed and then bleached again in a comparatively short time. The removal of the hair color under mild and safe conditions with either oxidative or non-oxidative agents has not been possible up to now.